The present application is based on Japanese patent application no. 2000-072925, filed on Mar. 15, 2000, which is hereby incorporated by reference in its entirety.
1. Field of the Invention
This invention relates to a sewing material supporting device, and a sewing machine having the same.
2. Discussion of the Background
Japanese Patent Laid-open Publication No. 2000-42276 discloses a sewing material holding device. This sewing material holding device includes a stationary main arm which extends in one direction, a movable auxiliary arm pivoted to the main arm and extending in the one direction, an urging member which urges the movable auxiliary arm for closing the same and an engaging portion provided on the movable auxiliary arm and maintaining, when operated, an open condition of the movable auxiliary arm. In this sewing material holding device, before a sewing material is held between the main arm and the movable auxiliary arm, a wide gap or clearance is defined therebetween. And when the engaging portion is released, the urging member causes the movable auxiliary arm to rotate to close the gap, thereby clamping or holding the sewing material between the arms.
Japanese Patent Laid-open Print No. Hei. 7(1995)-305257 discloses a rectangular tambour on which a fabric to be embroidered is mounted is tensioned. The mounted condition of the fabric on the tambour is maintained by a pair of clamp devices.
Japanese Patent Laid-open Print No. Hei.8(1996)-41774 discloses a rectangular tambour on which a sewing material is mounted in tension and which has a pair of opposed recesses. For holding the sewing material on the tambour, another frame is used whose projections fit into the recesses of the tambour via the sewing material.
In Japanese Patent Laid-open Publication No. 2000-42276, for clamping the sewing material between the main arm and the movable auxiliary arm, the movable auxiliary arm has to be rotated by the urging force of the urging member, toward the main arm by releasing the engaging portion. Due to the fact that a large gap is formed between the main arm and the movable auxiliary arm before the clamping is done, the user has to hold the sewing material until completion of the clamping. Such temporary holding of the sewing material is very cumbersome.
In Japanese Patent Laid-open Print No. Hei. 7(1995)-305257, the fabric which is in tension on the tambour is clamped by the clamp devices. Thus, it is also very cumbersome to hold the fabric until the clamping is completed.
In Japanese Patent Laid-open Print No. Hei.8(1996)-41774, holding the sewing material on the tambour is done by male-and-female engagement between the tambour and the frame. Until such engagement is completed, the sewing material has to be held on the tambour temporally until the male-and-female engagement is completed.
A need exists to provide, for overcoming the aforementioned problems, a sewing material holding device and/or a sewing machine having such a holding device.
Accordingly, a first aspect of the present invention is to provide a sewing machine which comprises a sewing machine main body including a sewing mechanism, and a material holding device mounted on the sewing main body and having a first arm device and a second arm device between which a material is detachably held for being sewn by the sewing mechanism. At least one of the first arm device and the second arm device of the holding device includes a main arm protruding in a direction. A sub arm protrudes along the main arm and is capable of cooperating with the main arm to hold the material. A pressure contact part establishes pressure contact between a part of a protrusion edge of the sub arm with a protrusion edge of the main arm with defining a clearance between a base end portion of the main arm and a base end portion of the sub arm, the pressure contact between making it possible to hold the material temporarily. A clearance reduction device enhances a degree of holding the material by engaging one of the main and sub arms to the other.
A second aspect of the present invention is to provided a sewing machine of the first aspect, wherein at least of at least one of the first arm device and the second arm device of the material holding device includes a sewing material guide portion for guiding and putting the material between the main arm and the sub arm.
A third aspect of the present invention is to provide a sewing machine of any one of the first aspect and the second aspect, wherein the material holding device includes a long plate guide holding portion extending is a direction of intersect with the direction along which the main arm extends, at least one of the first arm device and the second arm device being slidably mounted on the long plate guide holding portion such that a clearance between the first arm device and the second arm device is made continually variable.
A fourth aspect of the present invention is to provide a material holding device mounted on a sewing machine, which comprises a first arm device and a second arm device between which a material is detachably held for being sewn by a sewing mechanism of the sewing machine, at least one of the first arm device and the second arm device of the holding device including a main arm protruding in a direction. A sub arm protrudes along the main arm and is capable of being coping with the main arm to hold the material. A pressure contact part establishes pressure contact between a part of a protrusion edge of the sub arm with a protrusion edge of the main arm with defining a clearance between a base end portion of the main arm and a base end portion of the sub arm, the pressure contact making it possible to hold the material temporarily. A clearance reduction device enhances a degree of holding of the material by engaging one of the main and sub arms to the other.
In accordance with the present invention the pressure contact part establishes pressure contact between the protrusion edge of the sub arm and the protrusion edge of the main arm while a clearance is defined between the base end of the main arm and the base end of the sub arm. Such pressure contact makes it possible to temporarily hold the sewing material. Since the sewing material is temporarily held by the pressure contact, the operator does not need to hold the sewing material.
In addition, the clearance makes the contact area between the main arm and the sub arm smaller, which makes it possible to move the sewing material, along the clearance defined between the main and sub arms to the formal holding position. Upon completion of the movement or transfer of the sewing material to its formal holding position, the clearance reduction device reduces the clearance, resulting in the main and sub arms approaching one another, thereby increasing the degree for holding the sewing material. Thus, holding or clamping the sewing material at the formal holding position is established.
The sewing material in accordance with the present invention and the holding device in accordance with the present invention can employ the following concepts. At least one of the first and second arm devices can have a guide portion which makes it possible to feed the sewing material between the main and the sub arms. Such a guide portion can form a slant surface which constitutes the clearance between the main and sub arms. The guide portion can be positioned at least at one of the protrusion edges of the respective main and sub arms.
At least one of the opposed holding surfaces of the respective main and sub arms can have high frictional resistance for enhancing the temporary and formal holding abilities. In this case at least one of the opposed holding surfaces of the respective main and sub arms is preferably has a high frictional property, i.e., it is formed of a high friction coefficient material such as rubber or is formed to have fine concave portions (or convex portions) such as a knurled surface for ensuring the holding of the sewing material.
At least one of the opposed holding surfaces of the respective main and sub arms preferably has a feature for enhancing the temporary and formal holding ability of the sewing material. Such a feature may be a convex or concave surface structure.
The material holding device can be incorporated into the sewing machine upon its assembly or can be added later to a commercial sewing machine. Whether or not the sewing machine has an embroidering function is irrelevant.
At least one of the first arm device and the second arm device preferably has a contact avoiding device which prevents contact between the clearance reduction part and the sewing material. As such a contact avoid means, a projection acting as a stopper is available. The contact avoiding device can be on at least one of the main and sub arms.
In the sewing machine in accordance with the present invention, the sewing mechanism can be of a well-known structure so long as the sewing material can be sewn while clamped or held between the first and second arm devices. Whether or not the sewing mechanism has an embroidering function is not important. Any sewing machine, whether it is designed for industrial use or domestic use, is available.
The first and second arm devices are preferred to be independent from each other and be placed in parallel to each other.
The material holding device can be a long guide holding portion which extends across the protruding direction of the main arm and on which at least one of the first arm device and the second arm device are slidably mounted so that the distance between the first arm device and the second arm device is made variable in a stepless fashion. In this case, only one of the first arm device and the second arm device is movable, or both are movable.
If one of the first arm device and the second arm device is made movable, the long guide holding portion is preferred to have an arm position indicator for recognizing the frequently used arm device. Employing such a concept, positioning one of the first and second arm devices can be done quickly. Preferably, the arm position indicator is in the form of at least one of a visible indication which makes it possible to recognize the frequently used slide position with the naked eye, audible indication which makes it possible to recognize the frequently used slide position by the ear, and touch indication which makes it possible to recognize the frequently used slide position by touch. Of course, at least two of these three forms can be employed, i.e., both visible indication and audible indication, both audible indication and touch indication, or both visible indication and touch indication.
In the case where at least one of the first and second arm devices is movable, the movable distance can be set to be xc2xc-5 times, or ⅓-3 times, the length of the movable arm device. However, such dimensions are not limiting.